JPH1170657A - Printing head and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the density irregularity caused by the change of the ink transfer amt. of a printing head of a dye evaporating type thermal transfer system which trimesters by evaporating ink, with the elapse of time. SOLUTION: The center part of an evaporation part V above the heater 46a of a transfer part T is constituted so that an ink 8 is hard to enter or does not enter to generate the evaporation of the ink 8 only at the boundary part of the evaporation part V. By this constitution, for example, the surface properties of columnar elements 47b being ink holding structures are changed by the adhesion of thermally deteriorated matter or the like to improve the wettability with the ink 8 and, as a result, a large amt. of the ink 8 penetrates into the center part of the evaporation part V to prevent a sudden increase in a transfer amt. In order to prevent the ink 8 from penetrating into the center part of the evaporation part V, a relatively large void is formed to the center part of the evaporation part V or a relatively large pure columnar element is provided to the center part of the evaporation part V.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called dye vaporized thermal transfer type printer head and a printer for vaporizing or evaporating ink and transferring it to a transfer medium such as printer paper.

[0002]

2. Description of the Related Art In recent years, for example, a color image processed by a personal computer or the like, or a color image captured by a video camera, an electronic still camera, or the like is printed out.
It is used for viewing and other purposes. For this reason, the need for a printer capable of obtaining high-quality full-color images has been increasing, especially for individuals and, for example,
There is a growing demand for relatively inexpensive printers for small offices called "small offices" or "home offices" to obtain high quality full-color images.

As color printer systems, sublimation type thermal transfer systems (or dye diffusion thermal transfer systems), melt thermal transfer systems, ink jet systems, electrophotographic systems, and thermally developed silver salt systems have been proposed. In particular, dye-diffusion thermal transfer systems and ink-jet systems can easily output high-quality images with a relatively simple device.

In the dye diffusion thermal transfer system, an ink layer in which a high concentration of a transfer dye is dispersed in an appropriate binder resin is applied to an ink ribbon or a sheet, which is coated with a dye resin which receives the transferred dye. Then, heat is applied to the so-called thermal transfer paper with a certain pressure, and heat is applied from above the ink ribbon or sheet by a thermal head (thermal head), and the transfer dye is thermally transferred from the ink ribbon or sheet to the thermal transfer paper according to the amount of heat. It is to let.

This operation is repeated for each of the image signals separated into yellow (Y), magenta (M), and cyan (C), which are the three primary colors of annihilation color mixture, for example.
A full-color image having continuous gradation can be obtained.

FIG. 25 shows a configuration of a peripheral portion of a thermal head of a printer according to this method.

The thermal head 101 is arranged to face the platen rollers 102. Between them, for example, an ink sheet 103 having an ink layer 103a provided on a base film 103b and a dyeing resin layer on the surface of paper 104b. The thermal transfer paper 104 coated with the (dye receiving layer) 104a runs while being pressed against the thermal head 101 by the rotating platen roller 102.

The ink layer 103 selectively heated by the thermal head 101 according to the image to be printed.
The ink in a is thermally diffused into the dyeing resin layer 104a of the thermal transfer paper 104 heated in contact with the ink layer 103a, and transfer is performed in a dot pattern, for example.

The dye diffusion thermal transfer method is an excellent technique which can easily downsize and maintain a printer, has an immediacy, and can obtain a high-quality image comparable to a silver halide color photograph. However, in this method, generation of a large amount of waste and high running cost due to disposable use of the ink ribbon or the sheet were major drawbacks. In addition, it is necessary to use thermal transfer paper, and this also raises a problem that the cost is increased.

[0010] The fusion heat transfer method can transfer plain paper, but also uses an ink ribbon or sheet, and thus has a problem of generating a large amount of waste and high running cost due to disposable use. The image quality was not as good as silver halide photography.

Although the heat-developable silver salt system has high image quality, the running cost is also high because dedicated photographic paper and disposable ribbons or sheets are used, and further, the system cost is high in this system. There were also problems.

On the other hand, the ink jet system is, for example, an electrostatic attraction system, a continuous vibration generation system (piezo system), a thermal system, as shown in Japanese Patent Publication No. 61-59911 and Japanese Patent Publication No. 5-217. In this method, ink droplets are ejected from nozzles provided in the printer head by a method such as a bubble jet method, and the ink droplets are attached to printer paper or the like to perform printing.

Therefore, plain paper transfer is possible.
Since the ink ribbon and the like are not used, the running cost is low, and there is almost no generation of waste unlike the case of using the ink ribbon and the like. In recent years, in particular, the thermal method has been widely used because a color image can be easily printed.

However, in this ink jet system, the density gradation in the pixel is basically difficult, and a high-quality image comparable to a silver halide photograph, which can be obtained by the above-described dye diffusion thermal transfer system, can be obtained in a short time. It was difficult to reproduce. That is, in the conventional inkjet method, since one droplet of ink constitutes one pixel, in-pixel gradation is difficult in principle, and high-quality image formation cannot be performed. Attempts have been made to express pseudo gradation by the dither method using the high resolution of the ink jet, but the image quality equivalent to that of the dye diffusion thermal transfer method cannot be obtained, and the transfer speed is significantly reduced.

Recently, an ink jet system has been developed in which two or three gradations are obtained in a pixel by using diluted ink. In particular, in the case of an image such as a natural image, a silver halide photograph or a dye diffusion thermal transfer system is used. It was difficult to obtain the same image quality as.

On the other hand, in the electrophotographic system, the running cost is low and the transfer speed is high, but the image quality is not as high as that of silver halide photography, and the apparatus cost is extremely high.

That is, none of the above-mentioned methods satisfy all the requirements of image quality, running cost, apparatus cost, transfer time and the like.

Therefore, as a color printer system capable of satisfying all of these requirements, a so-called dye vaporization type thermal transfer system has been proposed (see, for example, JP-A-7-89107 and JP-A-7-89108).

In this method, the ink is heated at the transfer portion of the printer head to vaporize or ablate (ab).
lation: Called "sporadic". ), The ink is caused to fly, and is adhered to the surface of a transfer-receiving body such as a printer paper, which is opposed to the ink via a gap of, for example, about 50 to 100 μm to perform transfer.

The transfer portion is provided with an ink holding structure having a concave-convex structure in which, for example, a large number of columnar bodies having a width or diameter of about 2 μm and a height of about 6 μm are erected at minute intervals of about 2 μm. A heater is provided below the holding structure to form a vaporizing section.

The following effects can be obtained by providing such an ink holding structure in the transfer section. That is, (1) the ink is spontaneously supplied to the vaporizing section by the capillary phenomenon. (2) Due to the large surface area, the ink can be efficiently heated. (3) By appropriately setting the height of the columnar body, a predetermined amount of ink can always be held in the vaporizing section. (4) Since the surface tension of the liquid generally has a negative temperature coefficient, the locally heated ink is subjected to a force directed to the outer peripheral portion having a low temperature, but its movement is suppressed to a minimum by the ink holding structure. Thus, a decrease in transfer sensitivity is prevented.

Therefore, by providing such an ink holding structure, it is possible to vaporize or evaporate an amount of ink corresponding to the heating in the vaporizing section and transfer it to printer paper or the like. Control, that is, density gradation within a pixel is possible. As a result, for example, a high-quality image comparable to a silver halide color photograph can be obtained.

Further, since it is not necessary to use an ink ribbon or the like, the running cost is low, and the transfer of plain paper can be performed by using ink having high absorbency with respect to plain paper. Cost reduction is also possible.

Further, since this method utilizes the vaporization or ablation of the ink, that is, the dye, the transfer portion of the printer head for heating the ink is pressed against a transfer target such as printer paper with high pressure. Needless to say, there is no need to make contact, and therefore, there is no problem of thermal fusion between an ink heating section such as an ink ribbon and a printer sheet, which may occur in other thermal transfer systems.

[0025]

This dye vaporization type thermal transfer system, like the above-described dye diffusion thermal transfer system, has features such as miniaturization of a printer, ease of maintenance, immediacy, and high quality of an image. In addition to this, it is an excellent technology that can achieve reduction in waste and reduction in running cost due to non-use of ink ribbon and the like, and can also reduce cost by using plain paper.

However, there is still room for improvement in the conventional printer using this method.

That is, in the printer of this type, as described above, the ink held in the vaporizing part of the transfer part of the printer head is vaporized or spouted and transferred, but the transfer is proceeding stably. Occasionally, the center of the vaporizing section is almost free of ink, and most of the vaporization of ink is
It was found to occur near the boundary of the vaporization section. On the other hand, for example, when the surface property of the columnar body of the ink holding structure changes due to the attachment of a degraded substance due to heat and the like and the wettability with the ink is improved, the ink penetrates to the center of the vaporized portion and is transferred. There was often a phenomenon where the sensitivity increased rapidly. As a result,
As time elapses, the density unevenness of the printed image increases, leading to a decrease in image quality.

Therefore, an object of the present invention is to make full use of the above-mentioned features of the dye vaporization type thermal transfer system so that the amount of ink vaporized or ablated in the vaporization section does not change even over time. An object of the present invention is to provide a printer head and a printer which prevent deterioration of image quality over time.

[0029]

According to a first aspect of the present invention, there is provided a printer head for heating and evaporating or evaporating ink by heating a plurality of minute inks provided on at least the heater. An ink holding structure having gaps and allowing ink to penetrate and hold the micro gaps by capillary action, wherein the ink holding structure is provided at least on a peripheral portion of the heater. There is a gap above the center of the heater that is wider than the minute gap.

A printer head according to another aspect of the present invention has a heater for heating and evaporating or evaporating ink, and a plurality of minute gaps provided in a predetermined area including above the heater. A print head having an ink holding structure for injecting and holding ink by capillary action in those minute gaps, wherein the ink holding structure is on the heater except for the heater. It is formed with a gap wider than the minute gap in the portion.

A printer head according to still another aspect of the present invention has a heater for heating and vaporizing or evaporating ink, and at least a plurality of minute gaps provided on the heater. An ink holding structure for injecting and holding the ink by capillary action in those minute gaps, wherein the ink holding structure is provided on the inner periphery of the heater, An ink intrusion prevention wall for preventing ink from intruding above the center of the heater is provided, and the minute gap is formed outside the ink intrusion prevention wall.

Further, the printer of the present invention has a heater for heating and vaporizing or evaporating the ink, and at least a plurality of minute gaps provided on the heater. A printer head having an ink holding structure for injecting and holding ink by capillary action, wherein the ink holding structure exists at least on a peripheral portion of the heater, and a center of the heater is provided. The upper part is configured as a gap wider than the minute gap.

Further, a printer according to another aspect of the present invention has a heater for heating ink to vaporize or evaporate the ink, and a plurality of minute gaps provided in a predetermined area including above the heater. A printer head having an ink holding structure for injecting and holding ink by capillary action in those minute gaps,
The ink holding structure is formed on the heater with a gap wider than the minute gap in a portion other than on the heater.

A printer according to still another aspect of the present invention includes a heater for heating and vaporizing or evaporating ink, and at least a plurality of minute gaps provided on the heater. A printer head having an ink holding structure for injecting and holding ink by capillary action in those minute gaps, wherein the ink holding structure is provided on the inner periphery of the heater. In addition, there is an ink intrusion prevention wall for preventing ink from intruding above the center of the heater, and the minute gap is formed outside the ink intrusion prevention wall.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described according to preferred embodiments.

[First Embodiment] FIG. 8 is a schematic perspective view showing the appearance of a printer head according to a first embodiment of the present invention, and FIG. Are respectively shown in schematic cross-sectional views in a state of performing the above. FIG. 10 is a bottom view of the printer head, and FIG.
2 is a bottom view of the printer head with the cover of the ink storage section removed.

As shown in these figures, the printer head 1 has a head base 3 which also serves as a heat sink and is made of, for example, aluminum (Al). To a portion near the front end of the lower surface of the head base 3, a transfer portion and the like described later, for example, a heater chip 4 formed on a silicon substrate is adhered by, for example, a silicone-based adhesive. The position indicated by the alternate long and short dash line A in FIG. 9 is the flying center of the ink in each transfer portion. Note that this heater chip 4
A groove 31 is provided on the surface of the head base 3 so that the heater chip 4 can be evenly bonded to the bonding portion of, and an excess adhesive for bonding the heater chip 4 escapes into the groove 31. Has become.

A printed circuit board 5 on which a driver IC 51 (see FIGS. 9 and 11) for driving heat is mounted is also adhered to the head base 3 by, for example, a silicone-based adhesive. As clearly shown in FIG.
The mounting portion of the printed circuit board 5 of the head base 3 is formed in a recess that is lower by the thickness of the printed circuit board 5, and is mounted on the printed circuit board 5 when the printed circuit board 5 is mounted in the recess. The height including the driver IC 51 is substantially the same as the upper surface of the heater chip 4 attached in parallel with the printed circuit board 5.

The electrode pattern 4 on the heater chip 4
1 (see FIG. 11) and the connection portion between the driver IC 51 and the connection portion between the driver IC 51 and the wiring pattern 54 (see FIG. 11) on the printed circuit board 5 are not shown in the respective connection portions. In order to protect the bonding wires for connection, for example, a silicone-based coating material JCR (Junction Coating Resin) 52 is applied and thermally cured.

As shown in FIGS. 8 to 10, a cover 6 is adhered to a region covering a part of the printed circuit board 5 and a part of the heater chip 4 by, for example, a silicone-based adhesive. . On the other hand, as shown in FIGS. 9 and 11,
The head base 3 and the printed board 5 are provided with ink introduction holes 7 penetrating them. Then, for example, the ink 8 supplied from an ink tank (not shown) via a flexible pipe or the like (not shown) is supplied to the ink reservoir 61 formed in the cover 6 through the ink introduction hole 7, As shown in FIG. 11, the ink 8 is further supplied from the ink storage section 61 onto the heater chip 4 through a large number of ink supply paths formed by a large number of partition walls 42 and lid members 43, 4 are supplied to respective transfer sections (not shown) at the leading end.

As shown in FIG. 9, at the time of printing, the printer head 1 contacts the sheet 2 with the tip 3a of the head base 3 provided with the heater chip 4 in contact with the sheet 2, for example. On the other hand, it is held at a predetermined angle. Therefore, the distance between the transfer section (not shown) and the sheet 2 at the ink flying center A is always kept constant, for example, a gap of 50 to 500 μm.

At this time, as clearly shown in FIGS. 8 and 9,
The cover 6 attached to the printer head 1 is provided in advance with an inclined surface 6a corresponding to the inclination angle between the printer head 1 and the paper 2, so that the cover 6 does not interfere with printing. ing.

In FIGS. 9 to 11, reference numeral 53 denotes a wiring of the printed circuit board 5 which is not shown, for example, an FPC (Flexib).
le Print Circuit).

FIG. 1 is a plan view showing details of a transfer portion provided at the tip of the heater chip 4 and the vicinity thereof. Also,
FIG. 5 is a perspective view showing a portion of the heater chip 4 attached to the head base 3 with the cover 6 partially cut away. Further, FIG. 6 is a schematic sectional view mainly showing a portion of the heater chip 4, and FIG. 7 is an enlarged schematic sectional view of the transfer portion.

As shown in FIGS. 6 and 7, the heater chip 4 has a substrate 44 made of, for example, silicon, and a silicon oxide (SiO ₂ ) film 4
5, a high-resistance polysilicon film 46 serving as a heater is formed. When an insulating substrate such as a quartz substrate is used as the substrate 44, for example, the SiO ₂ film 4
The polysilicon film 46 may be formed directly on the substrate 44 without providing an insulating film such as 5.

As shown in FIG. 7, this polysilicon film 4
On 6, a common electrode 41a and an individual electrode 41b, each of which is made of, for example, an aluminum (Al) wiring pattern, are formed. FIG. 4 shows a pattern shape of the common electrode 41a and the individual electrode 41b in a plan view corresponding to FIG. 4, a polysilicon film 46 is formed below each of the electrodes 41a and 41b (see FIG. 7).
That is, the polysilicon film 46 functions as a part of the wiring in a portion where the electrode is present, and a portion 46a where the electrode is not present functions as a heater by resistance heating. The heater 46 selected by the common electrode 41a and the individual electrode 41b according to the image information to be printed.
a is heated to vaporize or evaporate the ink thereon,
The image is transferred to a transfer target such as a sheet 2 (see FIG. 9).

For example, in one heater chip 4, 20
The heater section 46a having a size of about 20 μm × 20 μm has about 8
256 pieces are formed at a period of 4.7 μm.
Since the number of heaters corresponds to the transfer of one dot, 300 d
A resolution of pi is realized.

As shown in FIGS. 6 and 7, on the heater chip 4, an SiO ₂ film 47 is formed as a protective film on the entire surface including the electrodes 41a and 41b. Then, as shown in FIG. 1 and FIG. 7, while surrounding each transfer portion T,
A partition wall 47a defining a supply path S for supplying ink to each transfer portion T, and a columnar body 47b forming an ink holding structure in each transfer portion T are formed as a part of the SiO ₂ film 47, respectively. ing. That is, for example, an SiO ₂ film 4 formed to a predetermined film thickness by a CVD (chemical vapor deposition) method.
7 is anisotropically etched by a predetermined depth using, for example, an RIE (Reactive Ion Etching) method using an etching mask having a predetermined pattern, so that the partition wall 47a, each columnar body 47b, and the portion of the protective film other than them are formed. It is formed at the same time.

As shown in FIG. 1, in each transfer portion T, for example, a columnar body 47b is formed in a square matrix of 9 × 9 (however, in FIG. 1, 7 × 7 is shown. 3) × 3 at the center are located on the heater section 46a. The size of each column 47b is, for example,
The width is about 0.2 to 10 μm and the height is about 2 to 15 μm, and these are arranged at intervals of about 0.2 to 10 μm, for example. The shape of each column 47b is not limited to a square column as in the illustrated example, but may be, for example, a column.

As shown in FIG. 1, a supply path S for supplying ink to each transfer portion T is defined by a partition wall 47a having the same height as the columnar body 47b in each transfer portion T. As shown in FIGS. 1 and 6, an ink flow path for supplying ink from the ink storage section 61 to these supply paths S includes, for example, a partition wall 42 formed of a sheet resist pattern, Each of them is formed in a tunnel shape by a lid member 43 made of a nickel (Ni) sheet (see FIG. 5).

At this time, as shown in FIGS. 1 and 6, on the transfer portion T side, the partition wall 42 made of sheet resist is, for example, 100 μm from the center of the heater portion 46a of the transfer portion T.
m to the position retracted by about m.
3 is, for example, 100 μm further from the end of the partition 42.
It is provided to a position retracted by about m. With such a configuration, an excessive supply of ink to the transfer portion T is prevented. That is, as shown in FIG.
Is supplied from the lid 43 near the outlet end of the lid 43 by the action of its wettability and surface tension.
The liquid surface rises along the wall surface of, and flows in a state where the liquid surface gradually decreases from there. A similar phenomenon also occurs near the end of the partition 42, and the ink 8 flows from the end wall surface of the partition 42 in a state where the liquid level gradually decreases. Therefore, if the partition wall 42 and the lid member 43 are too close to the transfer unit T, there is a possibility that excessive ink is supplied to the transfer unit T. If more ink than necessary is supplied to the transfer unit T, particularly to the heater unit 46a, the energy required to vaporize or evaporate the ink increases, and the transfer efficiency decreases. In addition, the configuration in which the partition wall 42 and the lid member 43 are provided by retreating, respectively,
This also means that it does not come into contact with a transfer target such as the sheet 2 (see FIG. 9) which is arranged to face the transfer portion T.

As shown in FIG. 1, the ink 8 flowing through the ink flow path defined by the partition 42 made of sheet resist forms a supply path S before each transfer portion T as the liquid level of the ink 8 drops. And separated into the supply paths S. Then, in each transfer portion T, as shown in FIG. 7, the ink 8 is held at substantially the same height as the upper surfaces of the partition walls 47a and the columnar bodies 47b. As described above, by providing the ink holding structure including the columnar body 47b in each transfer portion T, a constant amount of the ink 8 can be always held in each transfer portion T.

In each transfer section T, the heater section 46
The ink consumed by the heating of a is spontaneously replenished on the heater portion 46a by a capillary phenomenon due to the presence of the columnar body 47b. The flow of the ink 8 from the ink storage section 61 to each transfer section T described above is entirely caused by the spontaneous flow of the ink 8.

As shown in FIG. 1, in the first embodiment, in the supply path S in front of each transfer portion T, a substantially central position between a pair of partition walls 47a partitioning the supply path S is provided. An auxiliary wall 47c is provided. This auxiliary wall 47c is
For example, the partition wall 47a and the columnar body 47b are formed simultaneously with the SiO ₂ film 47. Therefore, the auxiliary wall 47c has substantially the same height as the partition wall 47a and the columnar body 47b described above.

The operation of the auxiliary wall 47c will be described below.

The retention of ink in each transfer section T is caused by the capillary action between the solid walls facing each other. For example, as shown in FIG. 3 (a), when the liquid between two vertical partition walls wets the partition wall surface, the contact angle between the liquid and the partition wall surface, the surface tension of the liquid, The liquid level is raised to a height h determined by the distance between the partition walls. In the case of the first embodiment, since the height of the partition 47a and the column 47b in each transfer portion T is lower than the above-mentioned h, as shown in FIG. The liquid level of the ink 8 is held at the height.

On the other hand, as shown in FIG. 3B, when the distance between the partition walls is large, the height h 'determined by the contact angle between the liquid and the wall surface on each vertical wall surface and the surface tension of the liquid.
, The liquid level gradually decreases, and the liquid level comes into contact with the bottom surface at a distance x from the wall surface. If this state occurs in the middle of the ink supply path, a portion where the ink is interrupted is formed in that portion, and the ink supply is interrupted.

As shown in FIG. 2B, when no auxiliary wall is provided in the supply path S adjacent to each transfer section T, the distance d between each pair of partition walls 47a defining the supply path S is set. ₁ is wide, the middle of this supply path S
The state of (b) occurs, and the supply of the ink to the transfer portion T may be cut off. That is, as shown in FIG. 3 (c), a change in the liquid level in each part of the ink flow path is such that the ink is composed of only the sheet resist partition walls without the lid material from the ink flow path in the portion having the lid material. The ink is supplied to the supply path S via the ink flow path, but because the supply path S is wide,
As shown in the drawing, a portion where the ink is interrupted is formed between the transfer portion T and the supply portion of the ink to the transfer portion T.

Therefore, in the first embodiment, FIG.
As shown in FIG. 2A, an auxiliary wall 47c is provided at a substantially central position between a pair of partition walls 47a that partition each supply path S. By providing such an auxiliary wall 47c, as shown in FIG.
distance between a d ₂ is smaller than half the distance d ₁ between the pair of partition walls 47a of the case without the auxiliary wall 47c. Therefore, as shown in FIG. 3D, the ink level in the middle of the supply path S rises, and continuous ink supply to the transfer unit T becomes possible.

Actually, a printer head in which the columnar body 47b is not provided in the transfer portion T was prototyped, and the height of the partition 47a was variously changed, and the skirt width x of the ink from the partition 47a (see FIG. 3).
(B)), the following results were obtained. The distance between the pair of partition walls 47a in the supply path S was set to about 60 μm. [Table 1] Height of partition walls Ink foot width x ─────────────────────── about 3.0 μm about 7.6 μm about 4.7 μm about 20 0.7 μm about 7.2 μm about 30 μm or more When the height of the partition wall 47 a is about 7.2 μm, there is no break in the ink from the supply path S to the transfer section T, and accurate measurement of x is not possible. could not. Also, originally,
The height h 'of the liquid surface at the point where the ink comes into contact with the partition walls (therefore,
The skirt width x of the ink should be constant irrespective of the height of the partition, but in the case of the configuration of this experiment, the side of the supply path S opposite to the transfer portion T has a high liquid level (about 25 μm). ) Since the ink flow path is connected to the tunnel-like ink flow path, the height of the ink liquid surface, and hence the skirt width x of the ink, changes depending on the height of the partition wall 47a.

From the results shown in Table 1, when the height of the partition 47a is about 5 μm, for example,
It can be seen that the columnar body 47b and the auxiliary wall 47c may be provided so as not to be separated from a by about 20 μm × 2 = 40 μm or more. However, actually, since the surface tension of the ink has a negative temperature dependence, it is preferable to arrange the ink closer to the surface.

If the height of the partition wall 47a or the columnar body 47b is increased, it is advantageous in terms of ink supply. However, since the ink liquid level in the vaporizing section rises and the amount of ink increases, the energy required for the vaporization is increased. Becomes larger, and, for example,
There is also a problem that it is difficult to form and etch the SiO ₂ film 47. Therefore, practically, the height of the partition wall 47a, the columnar body 47b, and the like is appropriately, for example, about 5 to 6 μm.

The printer head 1 according to the first embodiment
The ink 8 used for is composed of a dye, a solvent, and additives to be added as necessary, and the materials and the materials thereof are optimized so as to optimize transfer sensitivity, heat stability, image quality, storage stability and the like. Determine the compounding ratio.

The solvent of the ink has, for example, a melting point of 50.
C., and the boiling point is in the range of 250.degree. C. or more and less than 500.degree. C., and the thermal decomposition temperature is higher than the boiling point. When a solvent having a melting point of 50 ° C. or more is used, there is a possibility that an ink produced by mixing the solvent and the dye will coagulate during storage at room temperature, for example. Further, the boiling point of the solvent is 25
If the temperature is lower than 0 ° C., only the solvent may be selectively volatilized from the ink in a portion of the printer head exposed to the air near the transfer portion. Further, the boiling point of the solvent is 500 ° C.
With the above, not only the efficiency of ink vaporization becomes poor and the transfer sensitivity is lowered, but also the thermal decomposition process may proceed before the ink is vaporized. The molecular weight of the solvent is 4
It is preferably 50 or less. If the molecular weight is too large, the expansion coefficient at the time of vaporization becomes too small, and the transfer sensitivity may be reduced. Further, it is preferable that the solvent has a property of being spontaneously absorbed by the fiber of art paper, for example, from the viewpoint of transfer of plain paper.

In order to dissolve 5% by weight or more of the dye in this solvent, for example, the value of the solubility parameter of the solvent at 25 ° C. (defined by JH Hildebrand) is 7.5 to 10. It is preferably in the range of 5. If the solubility parameter is larger than 10.5, the solubility of the dye may be too low, and the reproducibility of the transfer sensitivity may be deteriorated by absorbing the moisture in the air. On the other hand, if the solubility parameter is smaller than 7.5, the solubility of the dye may be too low. Further, the solvent has a flash point of 1
It is preferably colorless at 50 ° C. or higher, with low toxicity to the human body.

Materials usable as the solvent include, for example, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate,
Phthalates such as diheptyl phthalate, dioctyl phthalate and diisodecyl phthalate; dibasic esters of fatty acids such as dibutyl sebacate, dioctyl sebacate, dioctyl adipate, diisodecyl adipate, dioctyl azelate and dioctyl tetrahydrophthalate Phosphoric acid esters such as tricresyl phosphate and trioctyl phosphate; organic compounds generally referred to as plasticizers for plastics such as tributyl acetyl citrate and butyl phthalyl butyl glycolate; ethyl naphthalene, propyl naphthalene, hexyl naphthalene; There are organic compounds in which an aromatic ring and an alkyl chain such as octylbenzene are combined.

The dye used in the ink has, for example, a boiling point in the range of 250 ° C. or more and less than 500 ° C., and
The thermal decomposition temperature is higher than the boiling point. If the boiling point of the dye is less than 250 ° C., when the printer head is preheated, a part of the ink may be vaporized, causing the transfer target such as paper to become dirty. On the other hand, the boiling point of this dye is 50
If the temperature is 0 ° C. or higher, the efficiency of dye vaporization becomes poor, not only the transfer sensitivity is reduced, but also the thermal decomposition process may proceed before the ink vaporizes. Further, the dye has an appropriate hue as a process color, has a molar extinction coefficient to the above-mentioned solvent of 10,000 or more, has low toxicity to the human body, and has high light resistance in the presence of the above-mentioned solvent. Preferably, there is.

The dye has a solubility parameter at 25 ° C. in the range of 7.5 to 10.5 as described above.
In addition, the vaporization rate when heated to 200 ° C. in air is 1 ×
It is preferably 10 ^-4 g / m ² sec or more, and the ratio of the residue that does not vaporize under the conditions is preferably 0.1% or less. If the solubility parameter of the dye is outside the above range, the dye will not be dissolved in the above-mentioned solvent in an amount of 5 wt% or more. If the heat resistance of the dye is low, or if the dye contains a large amount of non-volatile impurities and the proportion of the residue when heated to 200 ° C. in air is 0.1% or more, the transfer portion Deterioration of ink may accumulate in the ink holding structure, causing clogging of the printer head.

As the dye, for example, the applicant of the present invention has disclosed, for example, JP-A-8-244363 and JP-A-8-2443.
A dicyanostyryl-based yellow dye represented by the following general formula (1), which is proposed in JP-A-64 and JP-A-8-244366,

[0070]

Embedded image

A tricyanostyryl magenta dye represented by the following general formula:

[0072]

Embedded image

Anthraquinone cyan dyes represented by the following formula:

[0074]

Embedded image

And the like can be used.

These dyes can be used, for example, in air at 200
In order to reduce the proportion of the residue when heated to 0 ° C. to 0.1% or less, it is preferable to use after purifying by means of sublimation purification, recrystallization, zone melting, column purification, or the like. .

In order to adjust various physical properties of the ink, appropriate additives such as a surfactant and a viscosity modifier may be added as needed. However, these additives need to have the same boiling point as the solvent or the dye. For example, a fluorinated fatty acid ester, silicone oil, or the like can be used as the surfactant.

The ink is prepared, for example, by dissolving the above-mentioned dye in the above-mentioned solvent in a temperature range of 50 ° C. or less by 5 wt% or more, preferably 10 wt% or more, more preferably 20 wt% or more. At this time, in order to increase the solubility, two or more dyes may be mixed and used. Also,
At the same time, two or more solvents may be used as a mixture. Additives are added as needed. The ink preferably has a surface tension of 15 mN / m or more at 25 ° C. in order to efficiently supply the ink to the transfer section by capillary action.

Paper suitable for this printer system is, for example, plain paper such as PPC paper, or high-quality paper such as art paper. In order to obtain a high-quality image with high gradation and density, for example, As a resin that promotes the color development of a disperse dye or an oil-soluble dye, a special paper having a surface coated with polyester, polycarbonate, acetate, CAB, polyvinyl chloride, or the like may be used. Further, for example, in order to improve the ink absorption speed, it is effective to add a porous pigment such as silica or alumina.

FIGS. 23 and 24 show examples in which the printer head of the first embodiment is used for a serial printer and a line printer, respectively.

In the case of the serial printer shown in FIG. 23, as shown in FIG. 23, yellow (Y) is applied along a direction (Y direction in the figure) perpendicular to the feeding direction of the paper 2 (X direction in the figure). , Magenta (M) and cyan (C) printer heads 1 are arranged. In addition, a printer head for black may be further added. Each printer head 1
Is fixed to a movable piece 14 attached to the feed shaft 13 via a connecting member 15, for example. The rotation of the feed shaft 13 by a driving source (not shown) causes each printer head 1 to rotate.
Reciprocates in the Y direction in the figure. On the other hand, the paper 2 is fed in the X direction in the figure by the feed roller 11 every time one line is scanned by each printer head 1, and each printer head 1 1 is performed.

In the case of the line type printer shown in FIG. 24, the printer head 1 extends in a direction (line direction) perpendicular to the sheet feeding direction (X direction in the figure) as shown in the figure.
Are arranged for each color of yellow (Y), magenta (M), and cyan (C). It should be noted that a black printer head may be added to this. Paper 2 is fed by feed roller 1
1 is sent in the X direction in FIG.
At the position between the printer head 1 and the platen 12, printing is performed in line units by each printer head 1.

In the printer head according to the first embodiment described above, as shown in FIGS. 1 and 2A,
In the supply path S adjacent to the transfer portion T, an ink liquid level holding means including an auxiliary wall 47c is provided so that the ink is not interrupted in the supply path S. Therefore,
The replenishment of the ink consumed in the transfer unit T is reliably performed only by the spontaneous flow of the ink, and the occurrence of a printing failure due to the ink supply shortage is prevented.

[Second Embodiment] FIG. 12 shows a structure near a transfer portion of a printer head according to a second embodiment of the present invention.

In the second embodiment, for example, FIG.
In the configuration substantially similar to the first embodiment shown in FIG.
As shown in FIG. 12, the pattern of the ink holding structure by the columnar body 47b in the transfer portion T is provided so as to extend to a portion between the pair of partition walls 47a defining the supply path S and the auxiliary wall 47c.

Therefore, the columnar body 4 in the extension portion E
7b, the ink level in the supply path S can be maintained at substantially the same height as the transfer section T, the amount of ink held in the supply path S can be increased, and the ink Supply can be performed more reliably.

[Third Embodiment] FIG. 13 shows a configuration near a transfer portion of a printer head according to a third embodiment of the present invention.

In the third embodiment, for example, FIG.
FIG. 1 shows the auxiliary wall portion in the first embodiment shown in FIG.
As shown in FIG. 3, the transfer portion T is constituted by an extended portion E of the pattern of the ink holding structure by the columnar body 47b.

In this configuration, the ink liquid level can be held at substantially the same height as the transfer portion T at a location in the supply path S corresponding to the auxiliary wall of the first embodiment described above. In addition, a portion corresponding to the auxiliary wall and the partition 47
The liquid level of the ink can be raised also in the portion between a and a.

[Fourth Embodiment] FIG. 14 shows the structure near the transfer portion of a printer head according to a fourth embodiment of the present invention.

In the fourth embodiment, as shown in FIG.
The area near the transfer portion T of the printer head, including the partition wall 47a and the supply path S, is completely filled with the pattern of the ink holding structure by the columnar bodies 47b. Partition wall 47a
Is provided only on the front end side of the transfer portion T.

In this configuration, since the ink can be held in a considerably large area including the transfer portion T and the supply path S, the amount of ink held becomes very large, and the ink can be basically transferred in any direction. Since the ink can flow, the flexibility of ink replenishment increases, and it is possible to more reliably prevent the supply of ink in each transfer portion T from being cut off. On the other hand, there is a disadvantage that wasteful ink remaining without being used increases, and clogging or the like due to the remaining ink easily occurs.

[Fifth Embodiment] FIG. 15 shows a structure near a transfer portion of a printer head according to a fifth embodiment of the present invention.

In the fifth embodiment, as shown in FIG.
The width of the supply path S itself adjacent to the transfer portion T is reduced to achieve the maintenance of the ink liquid level there. However, in this case, if the width of the supply path S itself is too narrow,
On the contrary, there is a possibility that the absolute amount of the ink held there may decrease, and there is a possibility that the flow of the ink may be hindered.
Preferably, the width d ₃ of the supply path S itself is at least about 40 μm.

[Sixth Embodiment] FIG. 16 shows a configuration near a transfer portion of a printer head according to a sixth embodiment of the present invention.

In the sixth embodiment, for example, FIG.
In the configuration substantially similar to the first embodiment shown in FIG.
As shown in FIG. 16, the front end of the auxiliary wall 47c is arranged as close as possible to the heater 46a in the transfer section T. In this case, as shown in the drawing, the vaporizing portion and the auxiliary wall 47 formed immediately above the heater portion 46a in the transfer portion T are provided.
It is preferable that at least one row of the columnar bodies 47b be interposed between the front end portion and the front end portion c. This makes it possible to suitably replenish the ink consumed in the vaporizing section.

[Seventh Embodiment] FIG. 17 shows a configuration near the transfer section of a printer head according to a seventh embodiment of the present invention.

In the seventh embodiment, a configuration substantially similar to that of the sixth embodiment shown in FIG.
As shown in the figure, the front end of the auxiliary wall 47c is formed in a tapered shape. Thereby, the flow of the ink to the vaporizing section becomes smooth, and the supply of the ink can be suitably performed.

[Eighth Embodiment] FIG. 18 shows a configuration near the transfer section of a printer head according to an eighth embodiment of the present invention.

In the eighth embodiment, for example, FIG.
In the configuration substantially similar to the first embodiment shown in FIG.
As shown in FIG. 18, the partition 47a in the portion between the transfer portions T is eliminated, so that the transfer portions T communicate with each other.
With such a configuration, ink can flow between adjacent transfer portions T. For example, the original ink supply path to a certain transfer portion T may be disturbed, and ink supply to the transfer portion T may be performed. Even when the printing is not performed, the ink is supplied from the adjacent transfer unit T to the transfer unit T, so that the occurrence of the printing failure is avoided.

According to the first to eighth embodiments described above, the liquid level of the ink 8 is maintained at a predetermined level also in the supply path S adjacent to the transfer section T. Even if the supply of ink from the printer to the transfer unit T depends only on the spontaneous flow of the ink 8, it is always performed reliably and smoothly. Accordingly, it is possible to prevent density unevenness due to insufficient supply of the ink 8 to the transfer unit T, and generation of white stripes at the time of printing due to lack of supply of the ink 8 to the transfer unit T.

Next, ninth to eleventh embodiments of the present invention will be described with reference to FIGS.

As shown in FIG. 19A, in the transfer portion T, the columnar members 47b are arranged in the vaporized portion V immediately above the heater portion 46a similarly to the other portions of the transfer portion T. When the transfer is proceeding stably, FIG.
As shown in FIG. 7, the ink 8 hardly exists at the center of the vaporized portion V, and most of the ink 8 is vaporized near the boundary of the vaporized portion V. That is, at the center of the heater 46a,
Since the temperature is higher than its surroundings, the ink 8 at the center of the heater 46a moves outward due to the non-uniformity of the surface tension due to this temperature distribution. Almost disappears.

On the other hand, when the surface property of the columnar body 47b changes due to, for example, the attachment of a degraded substance due to heat, and the wettability with the ink 8 is improved, for example, the transfer at the center shown in FIG. As in the portion T, the ink 8 penetrates to the central portion of the vaporized portion V, and the transfer sensitivity of the transfer portion T sharply increases. In addition, as shown in the drawing, the leading edge position of the ink 8 between the transfer portions T, that is, the area and the perimeter of the portion without the ink 8 become non-uniform.

As described above, if the degree of penetration of the ink 8 into the vaporized portion V differs depending on the transfer portion T, density unevenness occurs between pixels for printing, and the quality of the obtained printed image deteriorates.
In addition, if there is no reproducibility at the position of the leading edge of the ink 8 at each transfer portion T, the transfer sensitivity characteristics (gamma characteristics) of each transfer portion T become unstable, which also causes density unevenness.

The ninth to eleventh embodiments described below are mainly for solving this problem.

[Ninth Embodiment] FIG. 20 shows a structure near a transfer portion of a printer head according to a ninth embodiment of the present invention. In the ninth embodiment, as shown in FIG. In the vaporized portion V of the transfer portion T, the columnar bodies 47b are arranged so as to be missing by a predetermined number from the original arrangement pattern.

That is, in the original arrangement pattern, as shown in FIG.
Although three pillars 47b are arranged, in the ninth embodiment, as shown in FIG. 20 (a), five of them are omitted at the center and only four at the four corners are left. . As a result, a relatively wide gap is formed at the center of the vaporized portion V, and as shown in FIGS. 20B and 20C, almost no ink 8 goes to the center of the vaporized portion V. ing. On the other hand, at the boundary between the vaporized portions V, the ink 8 is held at a predetermined height by the pillars 47b, and uniform transfer is always performed.

As described above, in each transfer section T, the ink 8 is not intentionally sent to the center of the vaporization section V, so that, as shown in FIG.
Is always almost the same in any transfer portion T, and the reproducibility of each transfer portion T is also improved. As a result, density unevenness in a printed image is significantly reduced.

[Tenth Embodiment] FIG. 21 shows a structure near a transfer portion of a printer head according to a tenth embodiment of the present invention. In the tenth embodiment, as shown in FIG. The arrangement pattern of the columnar body 47b in the vaporization part V and its periphery is different from the other parts.

That is, although the basic arrangement pattern of the columnar bodies 47b in the transfer portion T is a 9 × 9 square matrix, the pitch of the vaporized portion V on the heater portion 46a is larger than the pitch of the basic arrangement pattern. 4 pillars 4
7b is arranged. In addition, of the nine pillars 47b adjacent to the four sides of the vaporization part V, the four pillars 47b located at the center of each side are respectively displaced toward the vaporization part V, and the vaporization part V The distance between the four pillars 47b is adjusted.

Even with such a structure, a relatively wide gap is formed at the center of the vaporized portion V, and therefore, FIG.
As shown in FIG.
On the other hand, on the other hand, at the boundary portion of the vaporizing portion V, the columnar body 47
The ink 8 is held at a predetermined height by b, and uniform transfer is always performed.

[Eleventh Embodiment] FIG. 22 shows a structure near a transfer portion of a printer head according to an eleventh embodiment of the present invention. In the eleventh embodiment, FIG.
As shown in FIG. 2 (a), a square pillar-shaped solid pillar 47d having a cross-sectional shape larger than the other pillars 46b and slightly smaller than the size of the heater 46a is provided at the center of the vaporizing portion V. Provided.

Therefore, as shown in FIGS. 22 (b) and (c), it is assumed that the outer wall surface of the columnar body 47d functions as an ink intrusion prevention wall for preventing the ink 8 from entering the center of the vaporized portion V. At the same time, this outer wall surface and its surrounding columnar body 4
7b, the ink 8 having a predetermined height is held, and uniform transfer is always performed.

Note that the columnar body 47d may have a hollow cross-sectional shape having a void at the center thereof.

In the ninth to eleventh embodiments described above, the auxiliary wall 47c provided in the supply path S
The same effect as in the first embodiment described above can be obtained. Further, in the ninth to eleventh embodiments, the vaporization of the ink 8 occurs only at the peripheral portion of the vaporized portion V, and the ink 8 hardly enters or does not enter the central portion of the vaporized portion V. Therefore, the amount of ink vaporized in the vaporizing section V can be always kept constant, and the change with time can be prevented. As a result, unevenness in density between pixels during printing can be reduced, and deterioration of image quality over time can be suppressed.

[0117]

Embodiments of the present invention will be described below.

Example 1 FIGS. 1 and 2A are in accordance with the first embodiment already described.
A printer head provided with a transfer portion T having a columnar arrangement as shown in FIG. Each column 47b has a length and width of about 3 μm ×
A rectangular parallelepiped shape having a height of about 3 μm and a height of about 6 μm was arranged in a 9 × 9 square matrix with a center-to-center distance of about 6 μm. Adjacent transfer portions T are connected to the columnar body 47b.
A partition wall 47 having the same height of about 6 μm and a width of about 25 μm
a, and a supply path S is provided for each transfer section T. Further, approximately 6 μm in height is provided at a substantially central position of each supply path S.
An auxiliary wall 47c having a width of about 10 μm and a width of about 10 μm was arranged.

As the ink used for printing, the following [Chemical Formula 4]
Dicyanostyryl yellow dye shown in,

[0120]

Embedded image

A tricyanostyryl magenta dye represented by the following chemical formula 5:

[0122]

Embedded image

Anthraquinone cyan dyes represented by the following [Formula 6]

[0124]

Embedded image

Was added to dibutyl phthalate at room temperature for about 1 hour.
0 wt% was dissolved to prepare inks of each color of yellow (Y), magenta (M), and cyan (C).

When three printer heads were prepared and ink was introduced into each head, the ink spontaneously moved from the ink storage section (reference numeral 61 in FIG. 9) to each transfer section through each supply path. .

The three printer heads containing the inks of the respective colors were assembled in a serial printer, and sheets were set. Peach coated paper (manufactured by Nisshinbo Co., Ltd.) was used as the paper. The distance between the paper and the transfer section of each printer head is about 15
It was adjusted to 0 μm and printing was performed.

The print data changes the ON time per dot of the drive pulse to each heater in 16 steps while relatively moving each printer head and the paper, thereby forming an image of 16 gradations. Printed.

The highest sensitivities measured by the Macbeth densitometer were as follows for yellow (Y), magenta (M), and cyan (C).
They were about 1.8, about 1.9, and about 1.8, respectively. Also,
The maximum density unevenness measured by a microdensitometer (manufactured by Sakata Inx) when 256 heater sections of one printer head were driven under the same conditions was within about 1.9%. Further, the density unevenness between adjacent pixels was within about 0.9%.

In any of the 1 to 16 gradations,
There was no significant difference in density unevenness between the 256 heater sections, and a uniform transferred image was obtained.

Comparative Example 1 A printer head having the same structure as that of the above-described Example 1 was manufactured except that no auxiliary wall was provided in the supply path S, and printing was performed under the same conditions as in the Example 1.

The maximum sensitivities measured by the Macbeth densitometer were as follows for yellow (Y), magenta (M) and cyan (C).
They were about 1.8, about 1.9, and about 1.8, respectively.

Of the 1 to 16 gradations, in particular, at the time of high-density transfer with a long heater ON time, a transfer portion where the supply of ink was interrupted occurred, and several portions where white streaks appeared in the transferred image occurred. As a result, a uniform transferred image was not obtained.

Example 2 In accordance with the second embodiment described above, a printer head provided with a transfer portion T having a columnar arrangement as shown in FIG. 12 was manufactured. Each column 47b is a rectangular parallelepiped shape having a length and width of about 3 μm × about 3 μm and a height of about 6 μm, and is basically arranged in a 9 × 9 square matrix with a center-to-center distance of about 6 μm. did. Adjacent transfer portions T have the same height as the columnar body 47b and a partition wall 47a having a height of about 6 μm and a width of about 25 μm.
And a supply path S is provided for each transfer section T.
Further, an auxiliary wall 47c having a height of about 6 μm and a width of about 10 μm is arranged at a substantially central position of each supply path S. In addition, the columnar body 4
7b is arranged so as to extend to a portion parallel to a part of the auxiliary wall 47c.

When printing was performed under the same conditions as in Example 1, the highest sensitivities measured by the Macbeth densitometer were as follows for yellow (Y), magenta (M), and cyan (C), respectively.
It was about 1.8, about 1.9, and about 1.8. When the 256 heaters of one printer head were driven under the same conditions, the maximum density unevenness was within about 1.9%. Further, the density unevenness between adjacent pixels was within about 0.9%.

In any of the 1 to 16 gradations,
There was no significant difference in density unevenness between the 256 heater sections, and a uniform transferred image was obtained.

Example 3 In accordance with the third embodiment described above, a printer head provided with a transfer portion T having a columnar arrangement as shown in FIG. 13 was manufactured. Each column 47b is a rectangular parallelepiped shape having a length and width of about 3 μm × about 3 μm and a height of about 6 μm, and is basically arranged in a 9 × 9 square matrix with a center-to-center distance of about 6 μm. did. Adjacent transfer portions T have the same height as the columnar body 47b and a partition wall 47a having a height of about 6 μm and a width of about 25 μm.
And a supply path S is provided for each transfer section T.
Then, instead of the auxiliary wall, three columns of columnar bodies 47b are extended and arranged at substantially the center position of each supply path S.

When printing was performed under the same conditions as in Example 1, the highest sensitivities measured by the Macbeth densitometer were as follows for yellow (Y), magenta (M), and cyan (C), respectively.
It was about 1.8, about 1.9, and about 1.8. When the 256 heaters of one printer head were driven under the same conditions, the maximum density unevenness was within about 1.9%. Further, the density unevenness between adjacent pixels was within about 0.9%.

In any of the 1 to 16 gradations,
There was no significant difference in density unevenness between the 256 heater sections, and a uniform transferred image was obtained.

Example 4 A printer head having a columnar arrangement as shown in FIG. 14 was manufactured in accordance with the fourth embodiment described above. That is,
A columnar body 47b similar to that of the first embodiment is disposed on the entire surface including the transfer unit T and the supply path S, and the space between the transfer units T and the supply path S is provided.
No partition was provided to separate the spaces. However, only the front end side of the printer head is provided with a partition wall 47a having a height of about 6 μm and a width of about 15 μm, which is the same as the columnar body 47b, in order to prevent the ink from flowing to the edge of the chip.

When printing was performed under the same conditions as in Example 1, the highest sensitivities measured by the Macbeth densitometer were as follows for yellow (Y), magenta (M), and cyan (C), respectively.
About 2.1, about 2.2, and about 2.1. When the 256 heaters of one printer head were driven under the same conditions, the maximum density unevenness was within about 1.9%. Further, the density unevenness between adjacent pixels was within about 0.9%.

In any of the 1 to 16 gradations,
There was no significant difference in density unevenness between the 256 heater sections, and a uniform transferred image was obtained.

Example 5 According to the ninth embodiment described above, a printer head provided with a transfer portion T having a columnar arrangement as shown in FIG. 20A was manufactured. That is, in each transfer section T, the heater section 46a
A printer head having substantially the same structure as in Example 1 was produced except that the columnar members 47b were provided in a pattern excluding the upper five central ones.

When printing is performed under the same conditions as in Example 1 and the movement of the ink during the transfer operation is observed, FIG.
As shown in FIG. 7, in all the transfer portions T, the ink 8 has moved around by almost the same area.

The highest sensitivities measured with a Macbeth densitometer were about 1.7, about 1.8, and about 1.6 for yellow (Y), magenta (M), and cyan (C), respectively. .
The maximum density unevenness when 256 heater units of one printer head are driven under the same condition is approximately 0.6%, respectively.
%, About 0.7%, and about 0.6%. Further, the density unevenness between adjacent pixels is within about 0.4%,
It was within about 0.4% and within about 0.3%.

The maximum sensitivities after transferring 100 sheets of A6 paper are about 1.8, about 2.0, and about 1.7, respectively, and the maximum density unevenness is about 0.8% or less, respectively. , About 0.8
%, Within about 0.7%, and density unevenness between adjacent pixels were within about 0.5%, about 0.6%, and about 0.4%, respectively.

Example 6 According to the tenth embodiment described above, a printer head provided with a transfer portion T having a columnar body arrangement as shown in FIG. 21A was manufactured. That is, in each transfer section T, the heater section 46
A printer head having substantially the same structure as in Example 1 was manufactured except that the arrangement pattern of the columnar bodies 47b on and adjacent to a was changed.

When printing was performed under the same conditions as in Example 1 and the movement of the ink during the transfer operation was observed, FIG.
As shown in FIG. 7, in all the transfer portions T, the ink 8 has moved around by almost the same area.

The highest sensitivities measured by the Macbeth densitometer were about 1.6, about 1.7, and about 1.6 for yellow (Y), magenta (M), and cyan (C), respectively. .
Further, the maximum density unevenness when the 256 heater units of one printer head are driven under the same condition is about 0.7
%, About 0.7%, and about 0.6%. Further, the density unevenness between adjacent pixels is within about 0.4%,
It was within about 0.5% and about 0.3%.

The maximum sensitivities after transferring 100 sheets in terms of A6 are about 1.8, about 1.9, and about 1.6, respectively, and the maximum density unevenness is about 0.9% or less, respectively. , About 0.9
%, Within about 0.7%, and density unevenness between adjacent pixels were within about 0.6%, about 0.7%, and about 0.5%, respectively.

Example 7 According to the eleventh embodiment described above, a printer head provided with a transfer portion T having a columnar arrangement as shown in FIG. 22A was manufactured. That is, in each transfer section T, the heater section 46
On a, the height and width are about 16 μm × about 16 μm, and the height is about 6 μm.
A printer head having substantially the same structure as in Example 1 was prepared except that a rectangular parallelepiped column 47d of m was provided.

When printing was performed under the same conditions as in Example 1 and the movement of the ink during the transfer operation was observed, FIG.
As shown in the figure, in all the transfer portions T, the ink 8
It has invaded only on the periphery of the heater 46a.

The highest sensitivities measured by the Macbeth densitometer were about 1.8, about 1.9, and about 1.7 for yellow (Y), magenta (M), and cyan (C), respectively. .
Further, the maximum density unevenness when the 256 heater units of one printer head are driven under the same condition is about 0.5% each.
%, About 0.6%, and about 0.5%. Further, the density unevenness between adjacent pixels is within about 0.3%,
It was within about 0.4% and within about 0.3%.

The maximum sensitivities after 100 sheets of A6 conversion are about 2.0, about 2.0 and about 1.8, respectively, and the maximum density unevenness is about 0.8% or less, respectively. , About 0.9
%, Within about 0.7%, and density unevenness between adjacent pixels were within about 0.5%, about 0.5%, and about 0.4%, respectively.

Comparative Example 2 A printer head having a transfer portion T having a columnar arrangement as shown in FIG. 19A, that is, a printer head having substantially the same structure as that of Example 1 was manufactured.

When printing is performed under the same conditions as in Example 1 and the movement of the ink during the transfer operation is observed, FIG.
As shown in (1), the positions of the leading ends of the inks varied depending on the transfer unit T, such as the transfer unit T where the ink moves largely, the transfer unit T where the ink moves slightly, and the transfer unit T where the ink hardly moves.

The highest sensitivities measured by the Macbeth densitometer were about 1.6, about 1.7, and about 1.6 for yellow (Y), magenta (M), and cyan (C), respectively. .
The maximum density unevenness when 256 heater units of one printer head are driven under the same condition is about 1.1, respectively.
%, About 1.7%, and about 1.5%. Further, the density unevenness between adjacent pixels is within about 0.8%,
Within about 1.0% and within about 0.9%.

The maximum sensitivities after 100 sheets of A6 conversion are about 2.1, about 2.2 and about 2.0, respectively, and the maximum density unevenness is within about 1.9%, respectively. , About 2.6
%, Within about 2.0%, and the density unevenness between adjacent pixels were within about 1.2%, about 1.9%, and about 1.5%, respectively.

[0159]

According to the present invention, there is provided a heater for heating and evaporating or evaporating the ink, and a plurality of minute gaps provided in a predetermined area including above the heater. The printer head having an ink holding structure for allowing ink to penetrate into the minute gap by capillary action and retain the ink is configured such that the ink hardly penetrates into the center of the vaporizing portion on the heater.

Therefore, the vaporization or erosion of the ink substantially always occurs only at the boundary between the vaporized portions.
The amount of ink vaporized or eluted in the vaporizing section does not change even after the elapse of time. As a result, the occurrence of density unevenness in the printed image over time is prevented, and the deterioration of the quality of the printed image is prevented. .

Further, by controlling the energy supplied to each heater in accordance with the image data to be printed, it is possible to continuously control the amount of vaporization or ablation of the ink. It is possible to obtain a high-quality image that is high and capable of multi-value density gradation.

Furthermore, since the printer head and the printer of the present invention are basically of the thermal transfer type, they have features such as miniaturization, easy maintenance, immediateness, high quality of image, high gradation, and the like.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of the vicinity of a transfer section of a printer head according to a first embodiment of the present invention.

FIG. 2 is an enlarged schematic plan view of the vicinity of a transfer portion of the printer head according to the first embodiment of the present invention and a conventional printer head.

FIG. 3 is a schematic diagram showing a change in ink liquid level.

FIG. 4 is a schematic plan view showing an electrode pattern of the printer head according to the first embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view showing the appearance of the tip of the printer head according to the first embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view illustrating a structure of a front end portion of the printer head according to the first embodiment of the present invention.

FIG. 7 is an enlarged schematic sectional view showing a structure of a transfer unit of the printer head according to the first embodiment of the present invention.

FIG. 8 is a schematic perspective view showing the appearance of the printer head according to the first embodiment of the invention.

FIG. 9 is a schematic sectional view illustrating a printing method using the printer head according to the first embodiment of the present invention.

FIG. 10 is a schematic bottom view of the printer head according to the first embodiment of the present invention.

FIG. 11 is a schematic bottom view of the printer head according to the first embodiment with the cover removed.

FIG. 12 is an enlarged schematic plan view near a transfer portion of a printer head according to a second embodiment of the present invention.

FIG. 13 is an enlarged schematic plan view near a transfer portion of a printer head according to a third embodiment of the present invention.

FIG. 14 is an enlarged schematic plan view near a transfer portion of a printer head according to a fourth embodiment of the present invention.

FIG. 15 is an enlarged schematic plan view near a transfer section of a printer head according to a fifth embodiment of the present invention.

FIG. 16 is an enlarged schematic plan view near a transfer portion of a printer head according to a sixth embodiment of the present invention.

FIG. 17 is an enlarged schematic plan view near a transfer section of a printer head according to a seventh embodiment of the present invention.

FIG. 18 is a schematic plan view near a transfer section of a printer head according to an eighth embodiment of the present invention.

FIG. 19 is an enlarged schematic plan view and a cross-sectional view of the vicinity of a transfer portion of the printer head according to the first embodiment of the present invention.

FIGS. 20A and 20B are an enlarged schematic plan view and a cross-sectional view of the vicinity of a transfer portion of a printer head according to a ninth embodiment of the present invention.

FIG. 21 is an enlarged schematic plan view near a transfer section of a printer head according to a tenth embodiment of the present invention.

FIG. 22 is an enlarged schematic plan view and a cross-sectional view of the vicinity of a transfer portion of a printer head according to an eleventh embodiment of the present invention.

FIG. 23 is a schematic diagram showing a configuration of a serial type color printer.

FIG. 24 is a schematic diagram showing a configuration of a line type color printer.

FIG. 25 is a schematic view showing a configuration of a conventional sublimation type thermal transfer printer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printer head, 2 ... Paper, 3 ... Head base, 3
a: tip, 4: heater chip, 5: printed circuit board, 6
... cover, 7 ... ink introduction hole, 8 ... ink, 41 ... electrode pattern, 41a ... common electrode, 41b ... individual electrode, 42
... partition wall, 43 ... lid material, 44 ... silicon substrate, 45 ... Si
O ₂ film, 46... Polysilicon film, 46 a.
7: SiO ₂ film, 47a: partition wall, 47b: columnar body, 47
c: auxiliary wall, 47d: pillar, 51: driver IC,
61: ink storage section, A: flight center, T: transfer section, S ...
Supply path, E: extension part, V: vaporization part

Claims (22)

[Claims] 1. A heater for heating ink to evaporate or evaporate the ink, and at least a plurality of minute gaps provided on the heater and having a plurality of minute gaps. A print head having an ink holding structure that penetrates and holds the ink, wherein the ink holding structure is present at least on a peripheral portion of the heater, and a center portion of the heater is wider than the minute gap. A printer head that is configured in a gap. 2. The printer head according to claim 1, wherein said ink holding structure is provided in a predetermined area including above said heater. 3. The ink holding structure is configured by arranging a plurality of pillars close to each other, and the plurality of minute gaps are formed between the pillars so as to be continuous with each other. The printer head according to claim 1. 4. A plurality of pillars are substantially arranged in a matrix, and a predetermined region including a center portion of the heater has a predetermined number of pillars missing from the matrix. The printer head according to claim 3, wherein the printer head is configured in the void in a state. 5. A heater for heating and evaporating or evaporating ink, provided in a predetermined area including above the heater, and having a plurality of minute gaps, wherein the minute gaps have a capillary phenomenon. A print head having an ink holding structure for allowing ink to penetrate and hold the ink, wherein the ink holding structure has a gap on the heater that is wider than the minute gap in a portion other than on the heater. The printer head that is formed. 6. The ink holding structure is configured by arranging a plurality of pillars close to each other, and the plurality of minute gaps are formed between the pillars in a state of being continuous with each other. The printer head according to claim 5. 7. The printer head according to claim 6, wherein an arrangement interval of the column on the heater is larger than an arrangement interval of the column in a portion other than on the heater. 8. A heater for heating and evaporating or evaporating the ink, and at least a plurality of minute gaps provided on the heater and having a plurality of minute gaps. A print head having an ink holding structure for invading and holding the ink, wherein the ink holding structure is provided on an inner side of a peripheral portion of the heater, and the ink is held in a central portion of the heater. A printer head having an ink intrusion prevention wall for preventing the ink, and the minute gap being formed outside the ink intrusion prevention wall. 9. The printer head according to claim 8, wherein the ink holding structure is provided in a predetermined area including above the heater. 10. The ink holding structure, wherein a plurality of pillars are arranged close to each other, and the plurality of minute gaps are formed between the pillars so as to be continuous with each other. The printer head according to claim 8. 11. The method according to claim 11, wherein the ink holding structure comprises a plurality of first
And a second pillar provided on a central portion of the heater and having a diameter larger than that of the first pillar, and an outer wall surface of the second pillar has the ink penetration. The printer head according to claim 10, wherein the printer head forms a prevention wall. 12. A heater for heating and evaporating or evaporating ink, and at least a plurality of minute gaps provided on the heater and having a plurality of minute gaps, wherein the ink is supplied to the minute gaps by capillary action. A printer head having an ink holding structure that penetrates and holds the ink, wherein the ink holding structure is present at least on a peripheral portion of the heater, and on a central portion of the heater, A printer that is configured with a gap wider than the gap. 13. The printer according to claim 12, wherein the ink holding structure is provided in a predetermined area including above the heater. 14. The ink holding structure, wherein a plurality of pillars are arranged close to each other, and the plurality of minute gaps are formed between the pillars so as to be continuous with each other. The printer according to claim 12. 15. A plurality of pillars are substantially arranged in a matrix, and a predetermined region including a center of the heater has a predetermined number of pillars missing from the matrix. 15. The printer of claim 14, wherein the printer is configured in the void in a state. 16. A heater for heating and evaporating or evaporating ink, provided in a predetermined area including above the heater, and having a plurality of minute gaps, wherein the minute gaps have a capillary phenomenon. A printer head having an ink holding structure that allows ink to penetrate and hold the ink, wherein the ink holding structure is located on the heater more than the minute gap in a portion other than the heater. A printer formed with a wide gap. 17. The ink holding structure, wherein a plurality of pillars are arranged close to each other, and the plurality of minute gaps are formed between the pillars so as to be continuous with each other. The printer according to claim 16. 18. The printer according to claim 17, wherein an arrangement interval of the column on the heater is larger than an arrangement interval of the column in a portion other than on the heater. 19. A heater for heating and evaporating or evaporating the ink, and at least a plurality of minute gaps provided on the heater and having a plurality of minute gaps. And a printer head having an ink holding structure that penetrates and holds the ink, wherein the ink holding structure is provided on the inside of a peripheral portion of the heater, and ink is provided on a central portion of the heater. A printer having an ink intrusion prevention wall for preventing intrusion, wherein the minute gap is formed outside the ink intrusion prevention wall. 20. The printer according to claim 19, wherein the ink holding structure is provided in a predetermined area including above the heater. 21. The ink holding structure, wherein a plurality of pillars are arranged close to each other, and the plurality of minute gaps are formed between the pillars so as to be continuous with each other. The printer according to claim 19. 22. A method according to claim 19, wherein the ink holding structure comprises a plurality of first
And a second pillar provided on a central portion of the heater and having a diameter larger than that of the first pillar, and an outer wall surface of the second pillar has the ink penetration. 22. The printer of claim 21, wherein said printer comprises a barrier.